Vehicle spring



April 1944- w. c. TOLLZIEN 2,346,092

VEHICLE SPRING Fiied July 29, 1940 INVENTOR.

Ward C3. 75/( /ev1 ATTORNEY.

Patented Apr. 4, 1944 Ward C. T'ollzien, D Spring Perch (30.,-

etroit, Mich assignor to Inc., Lackawanna, N. Y., a

corporation of. New York.

Application July 29, 1940, Serial No; 348,219

Glaims.

This invention relatesto, vehicle springs of the multi-leaved elliptic or semi-elliptic type and the object of the invention is to provide a new and improved means for securing a predetermined area of frictional contact between successive leaves to thereby provide for the required reaction under specific load.

Springs of the stated type, as heretofore made, usually have the successive, leaves in surface contact throughout their length and the principal feature of. this invention resides in the provision of inserts of an-improved form hereinafter more fully described by means of which the leaves, at their free ends, are separated for a distance inwardly from the said end to predetermine the area of frictional contact between each. pair of leaves to secure, the desired reaction to a specific load and the area of frictional contact may be varied by varying the thickness of the insert causing separation of the leaves at their free ends to the required degree to provide a predetermined area of dynamic frictional contact to secure the desired dampening effect.

These and other objects and features of the invention are hereinafter more. fully described and claimed and, a spring structure. embodying my invention including my improved insert and manner ofmounting the same between the leaves is shown in the accompanying drawing in which Fig. 1 is. a side elevation, partly. in section, of a multi-leaved spring showing my improvedconstruction with the insertbetween the leaves when in spread position prior to assuming the normal relationship in pressure contact.

Fig. 2' is an elevation, partly in section, showing two leaves of'a spring in normal relationship under load.

Fig. 3 is an enlarged sectional view taken on line 3--3 of Fig. 2.

Fig. 4 is a the aperture therein for receiving an insert.

Fig; 5 is a sectiontaken online 5-5 of Fig. 4.

Fig. 6 is a perspective view, partially in. section, showing oneform of element therefor.

Fig. 7 is a perspective view, partly in section, showing another form of insert.

plan view of a spring end showing:

insert and supporting Fig. 8 is a perspective View of another form of insert capable of use in structure.

A vehicle spring of the multi leaved typewith successive leaves in frictional contactthroughout their length, ashas commonly been the practice.-

heretofore, cannot be accurately calibratedlforcertain reactions under specific load and in such prior form of spring the only manner of varying the area of frictional contact between the leaves is by varying the length of the leaves which, in itself, would vary the character of reaction under specific load.

In my new and improved construction, while the leaves vary in length, as is the case with the usual multi-leaved type of spring, the successive leaves" are separated to a greater or less degree at the freeends to" secure the desired dampening efiect determined by the area'of successive leaves remainingin' frictional contact.

These and other'features and objects of the invention will be more readily understood from the followingdescription in conjunction with the drawing and it is to be understood that the term elliptic-type as hereinafter used in' the specification and claims is intended to-imply to the various forms either afourth, half or wholly elliptic form. I have, however, only illustrated the free end position of what is usually termed a halfelliptic type and not illustrating the commonly known manner of securing the spring'to asupport.

In'Fig. 1, I have'shown a spring formed of the leaves I, 2, 3, 4 and-5 and each of the leaves,

except the leaf I, is formed with an aperture 6' adjacent its end. The insert 7 shown in Figs. 1, 2, 3 and 6 is preferably formed of black rubber stock of a-cylindrical' form which is flexible. To support such-an insert in the aperture 6 Ma leaf I provide afianged sheet metal cup 3 in which the flange 9- overlies the upper surface of the spring surrounding theaperture 6. The insert is of such thickness, transversely of the leaves, that when seated in the cup, a portion thereof projects upwardly from the cup, as will be understood fully fromFigs. 1 and 6. The inserts, as shown in Fig. 1, are-in normal shape but, when the'leaves have been mounted in contact with one another, the portion of the insert projecting from the cup'will be deformed to provide a peripheral flange of rubber I 0 between the flange of the cup and: the under surface ofthenext adjacent leaf.

The said flangeofthe cup is connected with the body of the-cup by-acurved portion I I which permits the rubber insert 1 to readily-flow under the presure between the springs to form the flange H]. The thickness of the flange plus the thickness of the rim of the cup determine the angle at which'the-leavesare spread apart as illustrated diagrammatically by the angular space'lr shown in Fig; 1. Thus the area of fric- 8 there is provided an integral portion tional contact between any two successive leaves is from this point of contact indicated at I3 in Fig. 2 inwardly to the point of support of the leaves (not here shown). This angular space 12 may be varied by varying the length of the cylindrical insert between successive pairs of leaves or the inserts may be all the same length and if of the same length the angular space separating the same may be varied by varying the depth of the cup. Thus, by one structural arrangement or the other, the area of frictional contact between the leaves may be varied to provide a spring having a predetermined reaction under load. v

The rubber insert above described is bestprovided by use of the commonly known black rubber stock of uniform hardness namely, at 72 degrees F., 63 to 67 and at zero F., 75 maximum no a Shore durometer. The tensile strength should be approximately 3200 pounds per square inch, an elongation of 600 per cent and a compression set test equal to 400 pounds pressure on the rubber section used in an oven at 158 degrees F. for 22 hours, the dimensions being taken ten minutes subsequent to the removal from the oven set test.

The invention, however, is not confined to the specific rubber composition as other materials may be used as, for instance, an asbestos washer M indicated in Fig. 7 or rubber or asbestos element shown in Fig. 8. In the snap in form shown in Fig. 7 I provide a sheet metal or wire structure having legs indicated generally at it, that practically fits the aperture 6 of the leaf shown in Fig. 4 or 5 leaving the peripheral flanged like portion of the washer l4 between the leaves with the wire elements having the ends l6 within the body of the washer. The wire members snap into the aperture of a leaf and prevent lateral displacement. In the rubber element shown in Fig. I! of a diameter to practically fit the aperture of the leaf and the flange [8 lies between the leaves. The thickness of the washer M of Fig. 7 or of the portion iii of the form shown in Fig. 8 determines the extent to which the leaves may be separated at their free ends. It is preferable however that the said portions [4 and is. be of flexible rubber as is the case with the element 1 shown in Figs. 3 and 6. By such structural element the insert will flex in its plane and under ordinary conditions of use of the vehicle there will be no material slippage of the upper leaf in respect to the insert between a pair of leaves. The purpose of this invention is to provide a means for accurately determining the area of surface contact between the successive leaves and thus accurately determine the reaction under a specific load. The invention however is not confined to the use of black rubber stock as other flexible material, as hereinbefore stated, may be used but it is believed that the black stock or other material that may yield laterally by relative movement of a pair of successive pairs of springs leaves is the most desirable character of insert as friction between the insert and the contacting leaf is practically eliminated.

By means of either of the forms of insert'the leaf does not require to be shaped to provide a cup in which the insert is positioned, as shown and described in the pending application of Harold T. Dow, Serial No. 278,365, filed June 9, 1939, now Patent No. 2,227,300, dated December 31, 1940, but on the contrary may be simply formed with an aperture in which a cup or a portion of insert may be introduced to sustain the same in position.

With the cup and the use of an insert of rubber stock, such as has been described by Way of illustration, th degree of spread of the leaves may be readily varied either by varying the length of the cylindrical insert or varying the depth of the cup, which ineither case provides for a predetermined thickness of flange between the leaves to separate the same to the desired degree to thereby vary the area of successive pairs of leaves in frictional contact. It is further pointed out that the aperture of a leaf to receive the insert or the cup is at a point beyond the end of the next leaf of the series in contact therewith.

From the foregoing description it is believed evident that the structure and arrangement of parts described provides a spring structure in which the various objects and features of the invention may be attained.

Having thus fully described m invention, its utility and mode of operation, what I claim and desire to secure by Letters Patent of the United States is:

l. A leaf spring assembly comprising a plurality of leaves arranged in successive pairs of different lengths from a common point of fixed surface contact, each of the leaves except the longest leaf of the series having an aperture in the end portion thereof extending beyond the end of the contacting shorter leaf, a cup member having a body of a length greater than the thickness of the respective leaf and extending through the aperture and a peripheral flange overlying the periphery of the aperture, and a bearing element of a length greater than the depth of the cup and separating the leaves for a distance from their ends determined by the thickness of the portion of the bearing element projecting beyond the open end of the cup to thereby predetermine the surface area of the leaves in frictional contact.

2. A leaf spring assembly comprising a plurality of leaves arranged in successive pair of differing length from a common point of fixed surface contact, each of the leaves except the longest leaf of the series having an aperture-in the end portion thereof extending beyond the end of the contacting shorter leaf, a metal cup member having a cylindrical body portion prac-,

tically fitting the aperture, and a peripheral flange overlying the wall of the leaf about the aperture, a bearing element of rubber stock of a cylindrical form greater in length than the depth of the cup and providing an end portion subject to deformation under pressure contact between the leaves to provide a rubber flange overlying the rim of the cup and separating the leaves at their ends from surface contact to a distance toward the common point of, support determined by the thickness of the flange of rubber and of the cup to predetermine the remaining area of the leaves in surface contact.

3. A leaf spring assembly comprising a plurality of leaves of varying lengths in fixed surface contact at a point distant from their ends, each leaf except the longest leaf of the series having an aperture in the end thereof beyond the end of the next contacting shorter leaf, 9. flangedcup member in each of the apertures, a bearing element of yieldable rubber of a thickness greater than the depth of the cupand providing, under pressure of the assembled leaves,

a laterally unconfined flange of rubber between the flange of the cup and the surface of the leaf engaged by the bearing element, the depth of successive cups being varied whereb with a series of bearing elements of the same length a varied thickness 0i rubber flange is provided between successive pairs of leaves to separate the successive pairs, at predetermined distance from the ends thereof thereby determining the area remaining in frictional contact.

4. In a leaf spring assembly in which successive pairs of leaves are of differing lengths and the longer leaf of each pair having an aperture in the end portion thereof projecting beyond the other, a bearin element of rubber stock for use between the leaves, and a supporting element in each of the apertures in which a portion of the bearing element is restrained from lateral expansion and providing a portion of rubber stock between the leaves free to expand laterally and Of a thickness to separate the same from the free ends inwardly toward a common point of support a distance determined by the thickness of the rubber stock between the leaves when under load to thereby determine the area of the leaves remaining in frictional surface contact.

5. A leaf spring assembly comprising a plurality of leaves arranged in successive pairs of different lengths from a common point of fixed surface contact, each of the leaves except the longest leaf of the series having an aperture in its end portion beyond the end of the contacting shorter leaf, a bearing element of black rubber stock, a support therefor of cup like form having a rim at its open end and a body insertibl in the aperture, said bearing element being of a length greater than the depth of the cup and compressible to form a flange of rubber stock overlying the flange of the cup and separatin the leaves for a distance from their ends determined by the thickness of the bearing element therebetween when under load.

WARD C. TOLLZIEN. 

